Hey there man,
i have much problems thus far modeling organically - i'm workin on er though.... here is an example of the best head i've modeled (its hard to see most deformities because i hid them with texture muahaha... but its obvious to see the lack of detail and skill

) i no longer have this model and this is the only pic i've got...hehe, but i'm gonna start another head here this weekend and i'll post it up in the modeling section for help most likely. im guessing your going for more of a realistic looking head right?
Forgot to tell ya; this is a female head attempt (minus the hair)- however it hardly looks human